History is an art, not a science. Though history is studied, recorded, and analyzed, it does not fit into traditional sciences. History is too open to interpretation to be a solid science.
Historians have resisted their field being classified as a science. By using methods of pyschology and sociology, others have attempted to define the study of history into scientific terms, often missing key elements of the field of study. Historians also dislike history being referred to as a social science, preferring the term social study.
Though historians often look for trends in history, they do not believe in the cyclical theory of history that social scientist refer to. To quote two of my history professors: "History does not repeat itself, but it sometimes rhymes," and "History does not repeat itself, but idiots often do."